High Capacity Lossless Data Hiding in JPEG Bitstream Based on General VLC Mapping

As a branch of reversible data hiding (RDH), lossless data hiding (LDH) technique is important especially. Because LDH can not only reconstruct the cover image losslessly but also keep the visual quality of the marked image no degradation. This article proposes a new LDH scheme for JPEG images by general variable length code (VLC) mapping. In this scheme, the run size values are first reordered. Then a feasible solution space is generated. A simulated embedding model is established to find the optimal solution from the feasible solution space. The optimal mapping relationship is constructed according to the optimal solution. According to the optimal GVM relationship, the Huffman table in the file header is modified and then the additional data can be embedded by replacing the used VLC with the VLCs in the same mapping set. Experimental results demonstrate that most of the JPEG images using the proposed scheme cause less file size increments than previous RDH schemes while keeping the marked JPEG image with no distortion. Furthermore, the proposed scheme can obtain high embedding capacity.